Bag



Feb. 23, 1943.

Tf M. AVERY BAG Filed oct. 1o, 1940 tom fold;

Patented Feb. 23, 1943 BAG True M. Avery, Glens Falls, N. Y., assigner to Union Bag s Paper Corporation, Hudson Falls, N. Y., a corporation of New Jersey Application October 10, 1940, Serial No. 360,654

7 Claims. (Cl

The present invention relates to improvements in bags, and more especially tol those of the socalled duplex type composed of an outer bag or ply of paper or similar fibrous material and an Ainner liner or ply usually of an air and moisture proof material, and the primary object of the invention is to provide a novel structure in a bagoi' this type, which enables it to be sealed eifectively in the vclosing fold at .the bottom and/or top of the bag. y

Heretofore, dilllculty has been experienced in eifectively sealing the bottom or top of bags having inner liners, and especially in heat sealing bags of the usual socalled square type having nested tucks in their edges and composed of an outer bag or ply of paper or similar fibrous material and an inner liner composed oi heat sealable material, due to the fact that the inner fold lines of the infolded tucks of the inner liner were so close to the inner fold lines of the infolded tucks of the outer bag as to form a relatively thick ridge which prevented close contact of the .portions of the inner liner which extend intothe closing fold `or folds and serve to seal the end or ends of the bag, and frequently caused pin holes in the seal or seals which resultedjin leakage when the bag is filled with powdery or other finely divided material.

The presentinvention overcomes this dimculty in a simple and enective manner, although the improved bags may be made with the same facility as ordinary bags of this type, and without increasing the cost thereof. 1

In the accompanying drawing:

Figure l is a side elevation, partly broken away,

of a partially completed bag embodying the present invention;

Figure 2 is'a view of the improved bag ready is. completion by folding and securing of its bot- Figure 3 is a side elevation, partly broken away, of the completed bas: v

vFigure 4 is a vertical section of the completed bagron an enlarged scale, taken-on the line H in Fis. 3:

Figure 5 is a detail section, on an enlarged scale, taken on'the line l-l in Fig. 1;' and Figure- 6 is a detail section, on an enlarged scale. taken on the line l-C in Fig. 3.

Similar parts are designated by the same reference characters in the several figures.

The bag, as shown in the present instance, is'

of the so-called square type comprising an outer bag i formedfrom a tube of paper or similar at its vertical edges, and an inner liner l which may be formed into a tube from thin rubber sheeting vsuch as that known commercially as .Plioillm" which is vulcanizable or heat scalable by the application ofheat and pressure, or from "Cellophane of the ,wax-coated or heat 'scalable lvariety or other similar material, the inner liner being coextensive in length with the outer bag and extending across the front and rearv walls thereof at their inner sides, andvhaving tucks I foldedinwardly at its vertical edges and nested with or lying against the inner sides of the tucks 2 of the outer bag. The inner liner is preferably secured at each end to the outer bag by spots of adhesive. as indicated at l.

Heretofore, in the manufacture of bags of this type, the infolded tucksof the outer bag vand inner liner have been coextensive in area and in exactly superposed relation so that their inner fold lines were' coincident, or substantially so, ths forming relatively thick ridges which preeluded the complete sealing together directly of those portions of the inner liner which lie within the closing fold, and caused puncturing of the inner liner due to its abrupt creasing or folding thereof over such relatively thick ridges.

According to the presentl invention, each tuck` 4 of the inner liner is made deeper or extends into the bag to a greater extent than the respec.

tive tucks 2 of the outer paper or ber bag, so

that the inner fold line l of each tuck of the inner liner is oifset or removed inwardly to a substantial extent from the inner fold lines 8 of the respective tucks of the outer bag, thus providing extensions of the inner liner in the regions of the fold lines 1 which are directly'opposite to one another and the inner edges of which are removed inwardly from the fold lines I of the outer bag sufilcien'tly to permit these extensions oi' the inner liner to come into direct and intimate contact and to be attened into the form. or thin ilat strips. Consequently, when the opposite sides of the bag are pressed together, as across the portion thereof below the bottom fold line l when the closure seal is to be formed in the bottom closure ilap I in a bag of the square type, these strip-like extensions of the tucks of the inner liner will be flattened and their inner 4 fold lines 1 will be so far removed from the inner fold lines 8 of the tucks of the outer bag as to permit the opposed portions i0 and Il of the liner which lie within the inner and outer walls of the closure told or nap l to come into direct I l v and intimate sealing contact with one another nbmug mgml having tucks 2 folded inwardly 55 along the line i2 between the inner edges of the tucks of the liner and to lie close to and make close sealing contact with the relatively thin extensions of the tucks of the liner as well as with the remainder of these tucks without obstruction by the inner edges of the tucks of the outer bag, thus forming an effective seal for thecomposed of a heat scalable material as described.v

The bottom fold 9 may then be folded and secured in closed position to complete the formation ci a square bag, either by heat sealing it by the exposed portion of the end of the inner liner, or by the application of an adhesive there to in the manner usual with square bags, as indicated in Fig. 2. The same sealing effect obtained in the bottom closure of the bag. as described above. may be obtained in making the closure for the mouth or top of the bag, it being understood that the tucks of the inner liner extend inwardly to a greater extent than .the tucks of the outer bag, throughout the length of the bag.

The improved bag structure provided by the present invention is particularly advantageous when employed in duplex bags of the type comprising an outer bag composed of a relatively thick and tough material such as kraft paper and the inner liner is composed of a relatively thin transparent or air and. moisture proof material such as Plioillm," Cellophane or the like and which is comparatively fragile. In such cases, although the inner fold lines of the infolded tucks of the outer bag will be relatively thick and will form ridges over which portions of the inner liner lie, the extensions of the inner portions of the infolded tucks of the inner liner inwardly beyond these relatively thick ridges enable these inwardly extended portions of the inner liner to ycome together into close and direct contact and iforrnl inwardly projecting strips or vextensions the inner edges of which are of much less thickness than that oi'v the folded inner edges of the tucks of the outer bag and they are spaced inwardly therefrom. Consequently, the portions of the inner liner lying within the front and back walls of the closure fold or ilap may be pressed together to make the seal without abrupt creasing or bending of the inner liner over such thick ridges as heretofore, thus avoiding leakage or puncturing of the inner liner at such points and, due to the thinness of the portions of the tucks ofthe inner liner adjacent to their inner edges, an intimate and effective seal is made between them and the portions of the inner liner within the front and back walls of the closing fold when these `portions of the inner. liner are pressed together.

Although preferably and as shown, the invention is applied to bags of the so-called square type employing a bottom fold or flap, and the closure seal is made in 'this fold or flap, it is to be understood that, if desired, the closure seal may be made in an end portion of the bag, as hereinbefore described, without folding this portion of the bag into a fold or nap, and that the invention may be applied to other duplex or multi-ply types of bags in which effective seal- 75 ing at the inner fold lines of a liner is desired.

I claim: 1. A bag structure comprising an outer bag and an inner liner, the bag and liner having nested infolded tucks in their opposite edges,

the tucks having fold lines at their inner edges, the inner i'old lines of the liner being substantially parallel to and spaced inwardly from the inner fold lines of the bag, the tucks in the liner 10 extending inwardly to a sufficient extent beyond the tucks in the outer bag to form strip-like extensions.

2. A bag structure comprising an outer bag and an inner liner, the bag and liner having l5 nested infolded tucks in their opposite edges, the

tucks having fold lines at their inner edges, the inner old lines of the liner extending longitudinally along and being spaced inwardly from the inner fold lines of the bag, the tucks in the liner extending inwardly beyond the tucks in the outer bag sufiiciently to fold into direct ilatwise contact with one another.

3. A .bag structure comprising an outer bag and an inner liner both having nested infolded tucks in their opposite edges, the inner edges of the tucks being dened by fold lines, the inner fold lines of the tucks in the liner extending longitudinally of and being spaced inwardly from the inner 'fold lines of the bag sufllciently g to form strip-like extensions of the tucks of the vliner inwardly beyond the tucks in the outer bag, and opposed portions of the liner in an end portion of the structure being united to one another and to said inward extensions of the tucks of the liner to form a closure.

4. A bag structure comprising an outer bag and an inner liner both having nested infolded `tucks in their opposite edges, the inner edges of the tucks being defined by fold lines, the tucks in the liner having their inner fold lines offsetinwardly beyond the inner fold lines of the tucks of the outer bag suillciently to provide the portions of the tucks of the liner extending inwardly beyond the inner fold lines of the tucks in the l outer bag adapted to flatten and contact with one another directly, and opposed portions of the liner in an end portion of the structure being v united to one another and to the inner fold lines and adjacent -attened contacting portions of 5o the tucks of the liner to form a closure.

5. A bag structure comprising an outer bag of `nbrous material and an inner liner of heat scalable material, said bag andliner having correspondingly arranged tucks folded inwardly at '55 their edges, the inner edges of the tucks being defined by fold lines, the inner fold lines of the liner being substantially parallel to and spaced inwardly from the inner fold lines of the bag, the tucks of the liner being deeper than w those of the outer bag. and providing strip-like opposed portions offset inwardly from the fold lines at the inner edges of the tucks of the outer bag, and opposed portions of the liner in an end portion of the structure being heat sealable to one another and to the inner edges of the tucks in the liner.

' 6. A bag structure comprising an outer bag of ilbrous material and an innerliner oi' heat sealable material, said bag and liner having correspondingly arranged tucks folded inwardly at their edges, the inner edges of the tucks being defined by fold lines, the inner fold lines of the liner being substantially parallel to and spaced inwardly from the inner yfold lines of the bag. the tucks ci' the liner being deeper than thoae of the outer baz and forming ,stun-like extensions ot the liner disposed inwardlybeycnd the inner fold lines of the 'tucks offtheoutet beg and ioldable togethery natwise; ande-the linen having opposed portions in an endiportion of the structure which are`heet vsealed to one une other and to the inward extensions ot, the liner.l

'7. A has structure oompmnglfmouterim of relatively thick liner off' relatively thin neat transversely toiorm entendiei's'ure.v ,und liner having correspondingly vtucks -folded inwardly et their edges, the edges tossiciextensionsoftheliner.

` .mnxu'evmr.

o! the tucks bein! defined by fold lines, the lnner fold lines o! the liner being v parallel to and spaced inwardly from the inner told lines ot the beg, the tucks o! the liner being deeper than those ofthe outer bag and forming strip-like extensions et their inner edses which ere folded l netwise into` direct contact in theend closure f- 'bey'ond the inner edzes o! the tucks o! the has, 1 1 `andthe liner havin! Opposed portions in the end one another' and cloeurewhichereheatsesledto 

